Robots: Zoobotics

A new generation of animal-like robots is about to emerge from the laboratory

UNTIL recently, most robots could be thought of as belonging to one of two phyla. The Widgetophora, equipped with claws, grabs and wheels, stuck to the essentials and did not try too hard to look like anything other than machines (think R2-D2). The Anthropoidea, by contrast, did their best to look like their creators—sporting arms with proper hands, legs with real feet, and faces (think C-3PO). The few animal-like robots that fell between these extremes were usually built to resemble pets (Sony’s robot dog, AIBO, for example) and were, in truth, not much more than just amusing toys.

They are toys no longer, though, for it has belatedly dawned on robot engineers that they are missing a trick. The great natural designer, evolution, has come up with solutions to problems that neither the Widgetophora nor the Anthropoidea can manage. Why not copy these proven models, the engineers wondered, rather than trying to outguess 4 billion years of natural selection?

The result has been a flourishing of animal-like robots. It is not just dogs that engineers are copying now, but shrews complete with whiskers, swimming lampreys, grasping octopuses, climbing lizards and burrowing clams. They are even trying to mimic insects, by making robots that take off when they flap their wings. As a consequence, the Widgetophora and the Anthropoidea are being pushed aside. The phylum Zoomorpha is on the march.

Cecilia Laschi and her team at the Sant’Anna School of Advanced Studies in Pisa are a good example of this trend. They lead an international consortium that is building a robotic octopus.

To create their artificial cephalopod they started with the animal’s literal and metaphorical killer app: its flexible, pliable arms. In a vertebrate’s arms, muscles do the moving and bones carry the weight. An octopus arm, though, has no bones, so its muscles must do both jobs. Its advantage is that, besides grasping things tightly, it can also squeeze into nooks and crannies that are inaccessible to vertebrate arms of similar dimensions.

After studying how octopus arms work, Dr Laschi and her team have come up with an artificial version that behaves the same way. Its outer casing is made of silicone and is fitted with pressure sensors so that it knows what it is touching. Inside this casing are cables and springs made of a specially elastic nickel-titanium alloy. The result can wrap itself around an object with a movement that strikingly resembles that of the original.